Abstract
Purpose: :
To evaluate the usefulness of HbA1c measurement in a middle-aged non diabetic cataract surgery patients in order to identify those at high risk of diabetes, defined as HbA1c ≥ 6% according to the International Expert Committee ADA/EASD/IDF report.
Methods: :
Prospective observational study. Consecutive subjects aged from 40 to 64 years who underwent cataract surgery from March to June 2009. Patients with prior steroid use (n=8), congenital cataract (n=1), known (n=54) or unknown (based on fasting glucose ≥ 126 mg/dl; n=6) diabetes were excluded. Baseline patient characteristics, ocular history (myopia, previous ocular surgery, trauma or inflammation), body mass index (BMI) and waist circumference were recorded. Fasting blood glucose, post-prandial capillary glucose and HbA1c (DCA 2000, Bayer Diagnostics) were measured. Analyses were performed using SPSS software version 14.0 for Windows (SPSS, Chicago, IL).
Results: :
Among the 132 non diabetic subjects aged 57±6 yrs (47% male, BMI: 26±4 kg/m2; 20% with BMI > 30 kg/m2; waist circumference: 93±13 cm, 45% with abdominal obesity), 52 (39%) patients had HbA1c ≥ 6% compared with 5.8% of a US population in the same age range (Selvin et al Diabetes Care, 2009). Mean fasting and post-prandial blood glucose were respectively 98±11 [73-122] mg/dl (42% > 100 mg/dl, defined as impaired fasting glucose) and 140±42 mg/dl [68-265] (45% > 140 mg/dl). Mean HbA1c level was 5.86±0.34% [4.9-6.8]. Fifty-four (41%) patients had cataract risk factors (RF): severe myopia (n=28), previous intraocular surgical procedures (n=20) or inflammation (n=6), and 78 (59%) no potential risk factors (no RF). BMI (26.4±4.4 vs 24.9±4.1 kg/m2; p=0.049) and waist circumference (95±14 vs 91±12 cm; p=0.116) were higher in no RF compared with RF group. While mean fasting blood glucose was slightly increased in no RF compared to RF patients (99±11 vs 97±11 mg/dl; p=0.146), HbA1c level was noticeably higher in no RF patients (5.92±0.34 vs 5.77±0.33 %; p=0.013). Additionally, HbA1c value was ≥ 6% in 46% of no RF vs 28% in RF patients (p=0.033).
Conclusions: :
Middle-aged patients undergoing cataract surgery represent a population at very high risk of diabetes, since the frequency of HbA1c value ≥ 6% is 7-fold higher compared with the general population. Ophthalmologists are therefore in the front line to prevent or delay the onset of diabetes. Among these cataract patients, they have the opportunity to identify individuals at high risk of diabetes based on HbA1c measurement and who might benefit from preventive interventions.
Keywords: cataract • diabetes • clinical (human) or epidemiologic studies: risk factor assessment